SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '20a9d69226d4baca8af703675b6cf1a3c2db33ffaf803b6912fb46835cdaadf3' 
  AND token = 'wUzGVKW/vZtEXG7W5OFP3SfDrNWjvzjOSQ8z7OlvgXE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}